Knowledge of familiar people is essential to guide social interaction, yet there is uncertainty about whether semantic knowledge for people is stored in a categorical structure as for objects. Four priming experiments using hard-to-perceive primes investigated whether occupation forms a category connecting famous persons in semantic memory. Primes were famous faces exposed for 17ms with masking, resulting in severely restricted awareness and thus precluding expectancy-based priming effects. Targets were consciously perceptible famous faces (Experiments 1-3), famous names (Experiment 3), or occupations (Experiment 4) representing either the same or different occupation to the prime. Significant priming demonstrated the operation of automatic processes, including spreading activation, among persons sharing a common occupation; this supports the categorical view. The direction of priming (faster/slower responses to same-occupation than different-occupation targets) was dependent on prime-target stimulus onset asynchrony (Experiments 1-3) and type of target (Experiment 4). This pattern of results is attributed to the Centre-Surround mechanism proposed by Carr and Dagenbach [Carr, T. H., & Dagenbach, D. (1990). Semantic priming and repetition priming from masked words: evidence for a centre-surround attentional mechanism in perceptual recognition. Journal of Experimental Psychology: Learning, Memory and Cognition, 16, 341-350]. These results support (a) the categorical structure of semantic knowledge for famous people and (b) the application of the Centre-Surround mechanism to the domain of person recognition.